Ophthalmic instrument



Oct. A21, 1952 c. A. ELLIS ET Al. 2,614,557

OPHTHALMIC INSTRUMENT -4 Sheets-Sheet 1 Filed Sept. 25. 1948 INVENTORS CHARLES A. E\.\ \s

HENRY B. COLE E0/EW@ ATTOEN Y Oct. 2l, 1952 .c. A. r-:LLls ET AL 2,614,557

' OPHTHALMICSTNSTRUMENT Filed Sept. 23. 1948 i Y 4 Sheets-Sheet 2 Sz 'lNvENTORs 79 CHARLES A. E\.L\s

v1; 4 HENRY E. coLE Oct. 21, 1952 c. A. ELLls ET AL OPHTHALMIC INSTRUMENT 4 Sheets-Sheet I5 Filed Sept. 23. 1948 ATTOR EY Oct. 21, 1952 l c. A. ELLIS ET AL 2,614,557

OPHTHALMIC INSTRUMENT Filed Sept. 23, 1948 4 Sheets-Sheet 4 I I I I |`I o z s 4 s y PLANe or- L-.Nses 0m Zwak v l AT1-OR y Patented Oct. 21, 1952 OPHTHALMIC INSTRUMENT .Charles A. Ellis, Southbridge, fMass.,- .and Henry B. lCole, East"Woodstock,'Conn., a's'signors to .American Optical Company;

Southbridge,

vMass., a voluntary association of Massachusetts v.Application September 23, 19,48, Serial No..-50,-764

l 11 elaims. (ci.` 12e-76.5)

This invention relates to .devices for testing Aand exercising the eyes land, fparticularly to Aan :improved stereoscopic ldevice. for use in the JeX- .aminationwof the Aeyes and the `correction- .of .defects such as excessive phoria, ocular image differences, ,and `departmes from Anormal stereoscopic or tridimensional vision. g

lA .principal object .of `the.:inventionis toprovide an 4improved instrument of the-abovecharacter for examning1--and :aiding fin .the correc- .tion .of faulty avisual perception, particularly :as .applied to binocular .or stereoscopic vision..

Another .importantobjectis to ,provide -an jm- .proved ldevice .of theA above -character foradeter'- miningvertical and lateral phorias ofga :pair uoi? eyesfand aiding in the A correction of .the pris'- lmatic vimbalance vof the Aeyes jointly or "inde- .pendently .of eachother'.

Another object is totprovide ;adevice;of"fthe above. character in which lthe .degree .of .convergence `for a given' accommodation range maybe varied.

'l AnotherY object is to` provide an instrument .of 4the above.' character designed `for :depth perception, 1thestereoscopic adjustments 'being made by the controlled:adjustments of independent targets or vcharts accordance with the readingsof a scalevorscales associated therewith.

Another object is toA provide an'improved device of the above character which presents -a pair of half-stereograms Itothe eyes? by Vmeans of 4which the-correct optical positions inrspace for true stereopsisareiobtained. l

Another object is 1to-provide Van instrument vof thel above-character which will provide normal accommodation-convergence relationship @while being used or, 'if desired, provide abnormal 'accommodation-convergence patterns, -theaprovisional-lowing -emphasisto be placed upon either accommodation orv convergence as desiredfin -aecordance with the particular test or trainingprocedure involved. l y Another'object is -to--provide aV device lof .the

above character Wit-h means whereby the targets lor Ychartsmay vbe individually and `independent- Aly orv simultaneous-1y moved vtowardA or away from one another at a specific-distance from thel view'- ing lenses with nochange 'in the demand forv accommodation to Vaid in fusion effort, each `target or chart Vbeing provided-*with*individual vertical adjustment means "to compensate for` vertical .deviations in the-patients eyes.

Another object is to provide a device ofthe 4above nature which vmay be simply and quickly adjusted to position the eyes of the patient'in .l

proper alignment'with the lenses".

`Another object is to provide .a device ofthe above character which may be yeasily operated "by either thev patient or the eye examiner. other objects and advantages ofthe' invention .willbecome apparent'from the fllowiiig'desoription taken inv .connection Withthe ,accompanying drawings, infwhich: f

Fig. l is a perspective View cfa stereo disparator embodying the present invention:

Fig. `2 is a top .plan view of the devicelfshown inFig. 1; 'l y Fig. 3 is a fragmentary sectional View of the device taken on line 3--3 of Fig. 2 andloking' in the directionof the arrows;

Fig. r4v is a .sectional View of the chart .supportstaken on line i--d of Fig. 3 andlookingin ther direction of the arrows; f

,-Fig. v5 is .a sectional view of an adjustment tube taken on line -5---5 of Fig. y2y and looking in the directonof'the arrows;

Fig. 6 is .a `sectional view through .a chart holder and support taken on y'liney 6-6 of. Figli and looking inthe direction of the arrows;

Fig. 7 isa fragmentary rear elevational View .of a chart holder .showing .the vertical adjustment means therefor;

Fig. 8 is a fragmentary sectional view ofthe base and adjustable support taken on line-.l-B of Fig. 1 and looking in the direction of thear` rows;

Fig. 9 is a fragmentary sectional view ofthe base clamping .arrangement .taken-on linev `9 --9 of Fig. 2 and lookingr in the directionr of the arrows; K

Fig. V10v is an exploded perspective view of the friction clamping` members shown in Fig. 9.; and

Fig. 11 is va .diagrammatic view of the scale means used for setting'the device for various testsor exercises and for 'indicating thesame.

` Instruments used. .for developing the eyes-in the past have proven eiective for revealing and correcting anomalies of near-point and far-point vision and give fairly accurate diagnosis ofthe stereo or tri-dimensionalvision Yofa patient. However, ithas been. found that prior art infstrurnents ofjthistypeare not versatile enough to contend with. all conditions which maybe found to .existwith respect to a patients vision since they do not embody means vfor making lall the adjustments necessary to change the Vvarious angles defining thecorrectvrelative positions'of the targets interms. ofany specied amount of variance fromv normal whereby. if desired, proper adjustment-Lof these angles can be madeso asy to maintain the appropriate conditions for @best possible fusion. The-present `disclosure embedles` means for making these .additienalwadjust-z ments and further improves uponthe prior art by providing proper scales and arrangementof parts so that the patients themselves .may easily and efficiently voperate the instrument to'. exercise their eyes withoutthe necessityof employingian expert lfor thisV purpose.

Referring to the drawings wherein like veuh-aracters of referencedesignate likeparts throughout the several views, the instrument embodying the invention comprises a heavy base II having an adjustable stand I2 pivotally connected thereto and adapted to be locked in adjusted position by manual operation of a knob I3. The base II is provided with spaced upwardly projecting lugs I4 and I5 between which is disposed the base portion of the stand I2, and stand I2 and lugs I4 and I5 being provided with concentric bores in which is located a spindle I8. The spindle I5 has a head portion I1 Adisposed on one end thereof of a size to reside within the bore in the lug I5 and has a bushing I3 disposed thereover adjacent the head portion I1, the bushing I3 and shaft I8 being held immovable by a taper pin I8 extending through them and into the lug I5.and held in place by a set screw 20.

The other end of the shaft I8 is threaded and engages' a threaded opening in a hub portion 2| formed on the inner side of the knob I3, the hub portion 2I being of a size to rotatably reside in `thebore 'in the adjacent lug i4. A second bushing 22 is mounted over the spindle I3 adjacent the hub portion 2l, the spaced bushings I8 and 22 having a tubular member 23 disposed between their inner ends and within the bore in the stand 2. The member 23 is split longitudinally thereof as at 24, each end portion of the member communicating with the split being cut away to form substantially V-shaped notches 25 and having fiat-bottomed notches 23 formed therein in substantial diametric opposition to the V-notches 25. The inner ends of the bushingsA I3 and 23 are provided with short beveled extensions 21 shaped in substantial conformity with the notches 25 and are adapted to reside therein when the deviceis assembled as shown in Fig. 9. The said ends of the bushings are also provided withv key-like projections 23 adapted to engage the notches 23. The bushing 22 is provided near one end with a groove 23 therein, which groove 23 is adapted to be engaged by a set screw inserted through a portion of the lug i4 to prevent rotation of the bushing 22. The base portion of the stand l2 is provided with a short protuberance 3l (Fig. 8) which extends within the hollow base II and has one end of a tension spring 32 connected thereto, the `other end ofthe spring 32 being secured to-a portion of the base I I as by the stud 33'. Thus,' substantially constant tension is placed'upon the stand I2 to provide ease in adjusting it at the desired angle. In operating the clamping device to position the stand I2 in desired position, the knob I3 is manually rotated to relieve pressure uponV the bushing 22, member 23 and bushing I8. Then after positioning the stand I2 as desired the knob I3 will be tightened to exert pressure upon the bushing 22, member 23 and bushing I3. This will cause the extensions 21 and 28 on the bushings I8 and 22 to engage the notches 25 and 26 in the ends of the tubular member 23, Ythe engagements between the extensions 28 and notches 26 preventing rotation of the clamp member 23. The engagements of the extensions 21 with the V-shaped notches 25 communicating with the split 24 act to spread the member 23 and cause the same to frictionally engage the walls ofthe bore in the stand I2 and by reason of the fact that the bushings I8 and 22, which carrythe extensions21, are keyed to the lugs I4 and I5 the said stand I2 will be locked in adjusted position.`

The stand I2, which may take the form of a gooseneck, is formed with a bifurcated upper end, the bifurcations 34 and 35 rotatably carrying a beam 31 therebetween on a shaft 36, which shaft is xedly secured in the bifurcations as by set screws 33 (Fig. 3). The beam 31 is adapted to tilt or rotate about the shaft 36 and to be locked in adjusted position by means of a clamping device which can be manually operated by 'a knob 33, the knob 33 being threadedly mounted on one end of a shaft 43 (Figs. l and 3) which shaft has its other end fixedly supported in the bifurcation 35, the shaft projecting through a slotted opening 4I in the beam 31 and through an enlarged circular opening in the bifurcation 34 in which a hub 33 on the knob 33 extends. Thus, when the knob 33 is tightened on the shaft 40 the hub portion 39 which extends through the opening in the bifurcation 34 will engage the side of the beam 31 adjacent the slotted opening 4I and will frictionally hold the beam 31 immovable.

Attached to the beam 31 as by screws 42 is a vertically `disposed supporting member 43 which carries at its upper end a lens carrying device 44 having appropriatelenses 45 mounted therein, the lenses 45 being of suitable dioptric power and incorporating base-out prisms. A chin rest 46 is mounted in the lower end of the member and ls adapted for vertical adjustment as by a conventional threaded shaft and nut arrangement 41. Grooved lens holders 48 are attached to the cylinder 44 adjacent the lenses 45 for insertion of additional lenses if desired.

The principal operating parts of the instrument are carried by the beam 31 whichiis preferably formed of metal or other nonwarping material. rIfhe beam 31 and lens carrying device 44 are disposed so that the beam 31 extends generally along the median line of the device 44.

Adjacent its end farthest away from the supporting member 43 the beam 31 is provided with a transversely extending tube 43 (Figs. 2 and 5) which is immovably secured in the beam 31. The tube 43 is provided with a longitudinal slot 50 in its lower surface on each side of the beam 31 and has a pair of slides 5I mounted for sliding movement therein. y A shaft 52 is located within the tube and has oppositely threaded portions 53 and v54 each of-whch portions carriesone of the slides 5I. A pair of knobs 55 are secured as by set screws or the like to the ends ofthe shaft 52 and upon revolving the shaft 52 by manual rotation of either of the knobs 55 the slides 5I can be made to-move toward or away from each other.

Short tubular guides 53 are mounted over the tube 43 adjacent each slide 5I Aand are attached to the slides 5I for movement therewith longitudinally of the tube 43 by screws51, the screws being inserted through the bottom portions of the guides 53 and slides 5I and through spacers 53 located in the longitudinal slots 53 between the guides andthe slides.-

Each guide 55 has a boss 53 located on its upper surface to each of which is pivotally secured, as by a screw 33, an angularly extending slide bar 62. Thus, when either of the knobs 55 are rotated to cause the guides 53 to move longitudinally of the tube 43, the bars 82 will consequently be moved accordingly an amount in vaccordance with the reading of a scale 6I (Fig. 2)

which is provided on the upper surface of the tube 43, the edge of one of the guides 56 being adapted to be aligned with the graduations on the scale 6I in positioning the bars 62.

Pi'*Phe'elt'arsf16,2'y areva'dapted to extend-ltovvardet-he supporting member 43 and have their ends adia-' centime-member 44-\providediwithslotted openingsl' 673,1A the" bars# 62"bsing-pivotallysupportedby studs-264 enjguldt-zsf` 85. r'l-hehguides V'65 vare movable-'longitudinally-ofte, sleever 66 uponmani-pu-lacent* the ends-of the sleeve- 166 inf-a manner vsirn- 68a/ onione `of -t'hefguides S65-and one end of the sleeve i166 frespectively. `l`Thus;:upon rotation ofA oney ofthe. knobs B'II-.a'threaded shaftA notshovvn) and simulating `thefshaftiv 52fwillfleetoperatedto movethefcguidesjl65i-. andlconsequentlyfthe ends-.of

seenathat; theespacingbetween the barsg-SZ and the beam-.-;31..f.can.. be f regulated .and the l angle which-s' the fbars.; B2 :make.-.fwith the beam 31 can betcorrespondingly;changed.

@Th-isi .adjustment providesffmeans on contr-oll'ng ther hqrizontalnadjnstmentgfof .1.a pair v:of stereogram targetsfor;,charts,fwhicheareimavable maadirectionlongitudinally.- bfsthe:bea'mta'lv and adaptedgtobesimnltaneouslyspaced.horizontally `With;respeot:;tooneianotherlin? aecordanceygith `de :member lf2 `.hat.fi.r,.1e i e longitudinal. `5reetapeular opening whieli-ts about the .fraile 61S, the. ,slide-member l2, therefore, -loeiirgadapted to ,slide freely along the rail 6,9. The, 4slide lrlemloer 'l2 supports. vthe stereqeram targets and for :this purposethere isprovided.a-breoketrle Which.isrxedly secured to fthe. Y.ripper Lsdrfaoe tof ,theslde member l2, withrearwardlyextending ringer-grips .14v bei-ne arraigned toomefsnde member 1'2 so that-the target supporting device. vcan .be easily lmoved along v.tlderail Y 6,9. l.

QA.` transversely disposed. tubular .holder 'I5 is dreary carried `by the. breeremaanafhas. sndebly mounted. therein;v a vl,pair of Fbushings 16 i (Fig. i 4) Whichareslidably located o n tubularslides 11. A roller 1841s attachedasby a; stud 'I9 Ato `eachv of .thee slides. ,11 and each is ,adapted .to l.extend throulghQa [longitudinal Yslot `in the holder 15 endltoqeneaee theouter edge. of 4ope of the forwardly or rearwardly von the rail 69 .the

erleulerlyydisposed iloars. G2 Will, through their engagement :by the.` rollersl't, cause the .slides ll .ehdLbushirlesfl 6A to. move. horizontally .Within they-holder 15 inV accordance with the Vangle describedby v'the relation of' the barsgEZ with the rail 6.9..

te ,edfthererlfasbya set throughl which prog'ectespacersiSSS:zwhi'chefsenve to connect angular target supportingzf:bracketsv 8l!A -to-theslidable, bushings 46;,theibraclsetsrrll andV ysiixacers'oBi l being; suitably-f connectedfllto @thev bushings'lfas bylzs'crewslor"rivetsw 1 l :The-*target supporting vbrackets AM: land/.-bush-- ing-s .16 'are individually-.fand :independently-:ade justable f longitudinally: 4on etherv slidesl :1 'I andiare adapted: to beretained-v adjusted enosi'tionsx by means tofs-'seti screws p85. T-he- Vsurface, cfa each of the `#slides flfiscprovided mthma-.iscalesf' graduated :in :millimeters adjacentfjthe..openings 82oa-nd ftheedges ofthe bushingsc areA adapted too-be aligned:withtheegra'duationsr-onitne scales. Thisyprovideslmeans.tforiindicating:'deoentration off-theftarget holders. 1 .e

Tnet-target supporting hrackegtsarll are each provided with can :upwardly @extending portion tovwhicn are riveted;or.V otherwisefxeidlyffsecured vertieal...supportng 5 platesil .ha-ving.=.gthelrfsides. l

bent .into Vsubstantially rufshapedzfportions .'IxfA irlv tealsupportingplates: 8.6areloeatedzrearivardly extending ilugsg92. ahavingi @threaded bores Iconcentric .with bores finz'thealealW-nldy Xteizldlfi shelf vi533.formedintegral with; he upperW-end c .and 7). The bores ar.e.each provided. to. receive a vertically extending t `rreagledadjusting screWfSd. vThe upper endofpaohcrew 9.4:S v

washer yB6, .spaced-slightly :below hlnob 93 and; f. target. Y holdings p :te ldit pwillf .beroailsedf .l

to-moveeither-upwardly... ing on the1directiemirrwhiohthe.knob Therefore, .thea rlietliflllf ther picturefor-targetl direction, leach :target fleeing '.{individdelly edf illstebleindependentlyfofthelotherz amount;

. of` suohzedjustmentroarl .berdeterminedinf ac- Gmane-ef-Wlll @Gele 9'7 provided .on :the-rear 0f 'techs of "the target .,lloldirie..v plates. ad ne sealesgsthavin entirrletepgraduatiopsfadapted to f be aligned '.Willl ."l'l L111313.63??:eliges Qf lthe itarjrget. supportineiplates ..86 :in positioning 4themlates 9.1. as desired.

In order .towasoertairi-pat aglanee the relative Spacing O the ,"ltalgels. 9 l `Y fromV the lenses 4,5,

vthe :upper .surface of *.tlie ibeam .-31 :isf provided with. .alongitudinal seele `Sl-l graduated) in` :fractional diopterslwith thelfocal plane .of ...the lenses (or/infinity) .beine the Zeropoint on saidY seele. and also inicentinreters with. thezero. point of misiatterfscale, being .theplane-ortlrfelenses. The slide. member 'IZ'hasan indioation 99 marked thereonwhich ,is vertically alignedwith the :planer of Vthe targetsilil andadapted nto ,in-. dieete the v.position `.of the? .targets l,on ...tliexsoale 98. ...Stops liuufa're. .adiustably .located ...on (theI target .eerryine .meerlsand Tare.eldap.teplfit be retained ln'adjusted position by means suchV as set screws IDI.

So that the targets 9| maybe clearly illuminated there is provided a light source comprising a suitable fixture |02 carrying a lamp |03, illumination from which is reflected by the fixture |02 onto the front surfaces of the targets 9 l, the lamp v|03 being connected to a suitable available source of current through a wire |03a.

In using the present device, the instrument is initially adjusted to comfortably accommodate the patient by elevating or depressing the portions of the instrument above the base. This is done by grasping the stand I2, turning the knob I3 to loosen the friction lock, moving the stand up or down to the desired position, and locking it in this position by tightening the knob I3. This is followed by adjusting the chin rest 4E.

In using the instrument to exercise the patients eyes, the scale 08 is used to indicate the distance at which the targets 9| are positioned away from the plane of the lenses 45. This is calculated from the portion of the scale graduated in centimeters,

this `portion being graduated to 20 centimeters inclusive, 20 centimeters being the focal plane of the lenses. The portion of the scale @8 calibrated in fractional diopter steps reading from the focal plane of the lenses with zero being positioned on this plane.

With the rear stop set so that the target holding device, in being positioned thereagainst, will position the targets 0| in the focal plane of the lenses, the knobs 55 can be operated to determine the separation of the targets in the focal plane of the lenses, while the control knobs 61 similarly determine their separation in the plane of the lenses.

The zero settings on the scales 6|, 65a and Etc indicate normal or perfect vision, representing the setting for orthoptic viewing withcentered targets. Scale-6| is graduated in centimeters and is calibrated to indicate up to 2cm. from the zero mark in a direction away from the midline and to 1/ cm. nearer the midline (Fig. l1). Scale 65a is provided with graduations representing displacements outwardly from the midline in amounts up to units from the Zero setting.

Because of the displacement of this scale 6ta from the plane of the lenses, in which plane these readings have the indicating meaning, the exact settings will vary somewhat, depending on the setting on the scale 6| in the focal plane of the lenses. This is compensated for by the scale 65a which lrepresent a reverse arrangement of the markings on scale 0 The mark which represents the reading on scale 6| is tov be considered the indicator to be -usedfin'making the setting on scale 60a. For example, Fig. 1l, which diagrammatically illustrates the use of these scales, shows that if the instrument is to be vset for orthoptic or normal viewing, wherein the de mands on convergence and accommodation will retain their normal relation, the setting on scale 6| will be zero. Then the zero graduation on scale 65awill become the indicator to be set at zero on the scale 65a. Scale |02 in Fig. ll is an imaginary scale positioned on the plane of the lenses and by setting the scales 6|, 65a. and 66a as described it will beunderstood that this will direct the path of the target indicated byr numeral |03 toward zero on the imaginary scale |02, which is the condition for orthopticviewing It is also to be understood that'Fig. l1 'illustrates the method of defining the adjustment ofthe path for only one'of the targetsl and that the lenses, for instance, the indicator 2 on scale 65a. will be set at zero on scale 66a. This will result in the targets traveling in a path as indi-y cated by |04 when the said targets are moved toward or away from the patient.

As a further example, it may be desired to set scale 6| at l and converge to 3 in the plane of the lenses, in which case scale 6| will be set at 1 and the indicator 1 on scale |55a`will be set at 3 on scaletta. This will result in path |05.

An instrument constructed according to the foregoing has many possibilities for stereo measurement and training. It has theadvantage of placing the targets in any suitable position and permitting the patient to develop his fusion.

It is to be understood that without instrumentation demands upon accommodation and convergence are normally correlated, and these requirements can be duplicated with the presently disclosed instrument when the targets follow the paths of orthoptic viewing, that is when the scales are set at zero and the target holders are adjusted to compensate for any decentering of the targets. Such conditions are desirable, for example, when it is desired to test the patients response to diagnostic targets under normal conditions of viewing 0r when it is desirable to stimulate accommodation and convergence in their normal association as. for example, at the conclusion of va visual training program designed to facilitate response of a lagging function or to discourage a tendency to excessive response.

However, in exercises for convergence weakness or where positive relative convergence is low, the practitioner or patient may elect to set the movable guide bars so that conditions for orthoptic viewing are established with distance fixation in the focal plane of the lenses, while the demand upon convergence is in excess of the normal amount associated with accommodation for any nearer distance. In exercising the eyes with adjustments made accordingly, such stimulative exercises are directed in a greater ratio toward theY convergence than to the accommodative function. In the case of divergence weakness, a pattern can be set up so that the demand for relative divergence is gradually increased until the patient establishes an adequate pattern of association between divergence and relaxation of accommodation. Similarly, patterns may be set up that require inhibition of convergence or of divergence with changes in the stimulus to accommodation.

From the foregoing it is evident that the pres` ently described device is an improvement'upon prior art devices of this character by providing simple vand efficient means for accomplishing all of the vobjects of the invention whereby the device can be more universally adjusted and has increased efciency in aiding in the correction of certain visual defects with means being provided to more easily and quickly set the instru# ment with greater exactness than has heretofore been possible so that the patients eyes can be more efficiently' examined andexercised in accordance with the desires of the practitioner.

While thenovel features A`of the invention have been`V shown and described and are pointedout in the annexed claims, .it will be understood that various omissions, substitutions-and changes in theA formation and details of the device illustrated, and in its operation, may be made by those skilled in the artwithout departing from the .spirit of the invention as expressed in the accompanying claims. Therefore,pit is, to. be understood that all matter set forth or shown is to kbeinterpreted as illustrative and not in a limiting sense.A

We claim:

1;..A deviceof the character described comprising a longitudinal support on which is slidablymounted altarget holding devicemovable longitudinally thereof and carryinga pair of spaced targets representing the stereoscopic complement of each other, a lens carrying device mounted on said support for viewing said targets, and means-on thel support coacting with said target holding device and said targets for changing the .spacing between the targets-as the holding device is moved, said means comprising a: pair of vslide members mounted on the target f holding device for movement normal to the directionof movement of the target holding device, resilient means urgingA said slide members toward each other, aY guideway on said support adjacent eachtarget having a pair of angularly disposed Y plane surfaces extending longitudinally thereof, and a roller carried by each of said slide members having a seat for engagingabout said surfacesV ofA a-,resp-ective guideway under the action-of said resilient means for simultaneously moving the targets towardv or away from each other;l as they'are moved respectively toward orf.' away from the lens carrying device so as to'causethetargets to followl pathsv disposed at angles in accordance with the angles at which the guideways extend with respect to saidl support.,

2. A devicenof'the character described comprising'alongitudinal support on which is slidably mountedl a target holding device movable longitudinally thereof and carrying a pair of spaced targets representing the stereoscopic complement of each other, a lens carrying device mountedf on said support for viewing said targets, means on the support coacting with said target holding 'device and said targets for changing the spacing between vthe targets as the holdingdevice ismoved, said means comprising a gudeway on said support adjacent each target, and: a follower associatedwith each target and cooperating with the adjacent guideway for si,- multaneously moving thatargets toward or away from eachother as'they are moved'respectively toward or away from the lens carrying device at angles inaccordance with the angles at which theguidewaysextend with respect toA saidl supportvand adjustment means for initially adjusting the angles ate-which said guideways extend with respectto said support, said adjustment means` beingfprovided at each endof` said guideway to alter the separation of the adjacent ends of said guideways whereby the angle of convergence or divergence of, the paths of the targets asv they are, moved longitudinally of the sup-port may be controlled.

43. Adevice of the` `character' described comprising alongitudinal support on which is slidably A mounted` a target holding ,device movable longitudinally" thereof and carrying a'pair of spaced",n targets representingvr the stereoscopic complement of each other, a lens carrying device mounted' on said. support for viewinggsaidtargets, means on the support coacting ywith said target holding device and said'targets for changing the spacingbetween the targets as the holdiing vdevice is moved, said means comprising a guideway on said support adjacent each target, anda follower associated with each target and cooperating with the adjacent guidewayjfor simultaneously moving the targets towardor away from each other as they are movedrespectively toward or. away from the lens carrying device at angles in accordance with the angles at .which the guideways extendwith respect vto said support andadjustment means for initially adjust,- ing .theI angles at vwhich said guidewaysextend with respect to saidsuppcrt, saidadjustment means beingprovidedat each end ofsaid. guide',- ways tocontroltheangle of convergence. or-.digvergence ofv the vpaths of ,the targets as., they .are moved longitudinally of thesupport, saidadjustment meansv comprising tubularv members spanningthe endsof said guideways, eachl tubular member carrying a rotatab-levrodk therein,...said rods having,oppositelythreaded portions, andthe guides. connecting. said guideways tov said threaded portions sothat upon rotationofeither of said rods the respectiveends of the guidways will be moved with `respect to one another to change the angle which, the guideways -make with said support.. y

4. A vdevice of the character described comprising alongitudinal support on'which is slidably mounted a targetv holding deviceA movable longitudinally thereof and carrying a painof spaced targets representing the stereoscopic complement ot-each other, a lens carrying dep-- vice mounted. on said support for-viewing. said targets.,- means on the support coacting with said target holding device and said targets for changing, the spacing between the targets asthehogld.- ingv device is moved, said means comprisinggf-a guideway'on said support adjacent each target, and av follower associated withA each target and cooperatingwith the adjacent guideway forsimultaneously movingl the targets toward or :away from each other as they are movedl respectively toward or away from: the lens-carrying device at angles in. accordance with the anglesA at, which the guideways exten-d. with respect to said suprport and adjustment -means, for 'initially adjusting the-angles at. which said guid'eways extend with respect to Vsaid support, saidA adjustment meansbeing Vprovided at eachend of said guideways toy control the anglaof convergence ordi.- vergence ofA` the .paths-of thetargets as. they aremovecl longitudinally of the support and-indicating means associated with eachofsaid `'adjustment means for indicating the amount of movement of the guideways.

5. A -deviceof the character describedcom, prising a longitudinal support onpwhich is slid,- Wably lmounted atarget holding l'deviceumovable longitudinallythereof and` carrying a pairef spaced targets representingH the stereoscopic complement of each other, a lens earryingdevice mountedonf said .support'for viewing said targets, angled guidewayson the supp-ort coacting with said target holding device and said targets for changing the spacing between the targets as the holding device is moved, :adjust:- mentdmeans for initially adjusting thev spacing of leachjend ofthe guideways with respect to the lcorresponding endv ofthe other guideway vwhere"- by the" anglesy at -which saidv guideways extend kwith respect to said support may be controlled,

and indicating means associated with said adjustment means for indicating the amount of movement of the guideways, said indicating means comprising graduated scales defining the spacing of the targets when in the plane of the lenses and when in the focal plane of the lenses.

6. A device of the character described comprising a longitudinal support on which is slidvchanging the spacing between the targets as the holding device is moved, adjustment means for initially adjusting the angles at which said guideways extend with respect to said support, said adjustment means comprising tubular members spanning the ends of said guideways, each tubular member carrying a rotatable rod therein, said rods having oppositely threaded portions, and guides connecting said guideways to said threaded portion so that upon rotation of either of said rods the guideways will be moved with respect to one another to change the angle which the guideways make with said support, and indicating means associated with each of said tubular members for indicating the amount of movement of the guideways, said indicating means comprising graduated scales provided on said tubular members, adjacent the guides connected to the guideways, said guides being aligned With the scale graduations in adjusting the guideways at desired angles, the scale on the tubular member adjacent the lens carrying device defining the spacing of the targets when in the plane of the lenses, and the scale on the other tubular member Adefining the spacing of the targets when in the focal plane of the lenses.

7. A device of the character described comprising a longitudinal support on which is slidably mounted a target holding device movable longitudinally thereof and carrying a pair vof spaced targets representing the stereoscopic complement of each other, a lens carrying device mounted on said support for viewing said targets, means on the support coacting with said target holding device and said targets for changing the spacing between the targets as the holding device is moved, said means comprising a guideway on said support adjacent each target, and a f-ollower associated with each target and cooperating with the adjacent guideway for simultaneously moving the targets toward or away from each other as they are moved respectively toward or away from the lens 'carrying device at angles in accordance with the angles at which the guideways extend with respect to said support and adjustment means for initially adjusting the angles at which said guideways extend with respect to said support, said adjustment means being provided at each end of said guideways to control the angle of convergence or divergence of the targets as they are moved longitudinally of the support, said adjustment means comprising tubular members spanning the ends of said guideways, each tubular member carrying a rotatable rod therein, said rods having oppositely threaded portions, and guides connecting said guideways to said threaded portions so that upon rotation of either of said rods the guideways will be moved with respect to one another to change the angleV which the guideways make with said support, and indicating means associated with each of said tubular members for indicating the amount of movement of the guideways, said indicating means comprising graduated scales provided on said tubular members adjacent the guides connected to the guideways, said guides being aligned with the scale gradua-tions in adjusting the guideways at desired angles, the scale on the tubular member adjacent the lens carrying device defining the spacing of the targets when in the plane of the lenses, and the scale on the other tubular member defining the spacing of the targets when in the focal plane of the lenses.

8. In a device of the character described, the combination of a base and a support carrying a target holder and sighting means for use in viewing target means held by said holder, said base having a pair of spaced uprights formed thereon, and the support having an end portion disposed therebetween for pivotal connection therewith, said uprights and said end portion having concentric openings formed therein, a friction clamp member disposed within the opening in said end portion and having one end engaged by a bushing ilxedly supported in the opening in one of said uprights and having its other end engaged by a second bushing slidably supported in the opening in the other upright, said bushings and clamp member having concentric openings therein, a shaft xedly mounted in said last named concentric openings, said shaft having a head portion engaging the outer end surface of said fixed bushing, and a clamp knob mounted on the other end of said shaft and adapted to bear upon the outer end of said slidable bushing, whereby upon tightening the knob pressure will be exerted upon said clamp' member to cause said clamp member to render said support immovable.

9, In a device of the character described, the combination of a base and a support carrying a target holder and sighting means for use in viewing target means held by said holder, said base having a pair of spaced uprights formed thereon, and said support having an end portion disposed therebetween for pivotal connection therewith, said uprights and said end portion having concentric openings formed therein, the opening in the end portion communicating with said base. a tubular friction clamp member disposed within the opening in said end portion, said clamp member having a longitudinal split with the end portions of the member adjacent the ends of the split being provided with V-shaped notches, a bushing xedly supported in the opening in one of said uprights and .engaging one end of said clamp member, a second bushing slidably disposed within the opening in the other upright and engaging the other end of said clamp member, said bushings having concentric openings therein and having extensions formed on the ends thereof engaging the clamp member, said extensions being of a size and shape to engage the notches in said member, a shaft xedly mounted in said last named concentric openings and extending through said clamp member, said shaft having a head portion engaging the outer end surface of said fixed bushing, and a clamp lknob mounted on the other end of said shaft to bear upon the outer end of said slidable bushing, whereby upon tightening the knob pressure will be exerted upon said bushings and clamp member to cause said extensions to be forced inwardly 13 of the notches in the clamp member to Widen the split and cause said clamp member to forcefully engage the support end portion and base to render said support immovable.

10. In a device of the character described, the combination of a base and a support carrying a target holder and sighting means for use in viewing target means held by said holder, a pair of spaced uprights formed on said base With an end portion of said support disposed therebetween for pivotal connection therewith, said uprights and said end portions having concentric openings formed therein, the opening in the end portion communicating With said base, a tubular friction clamp member disposed within the opening in said end portion, said clamp member havM ing a longitudinal split with the end portions of the member adjacent the ends of the split being provided with V-shaped notches, and further having notches formed therein in diametrical opposition to said rst notch, a bushing xedly supported in the opening in one of said uprights and engaging one end of said clamp member, a second bushing slidably disposed within the opening in the other upright and engaging the other end of said vclamp member, said bushings having concentric openings therein and having V-shaped extensions formed on the ends thereof engaging the clamp member, said extension being of a size and shape to engage the notches in said member and further having extensions diametrically opposed to said first extensions, said last named extensions being of a size and shape to said bushings and clamp `member to cause the extensions on the bushings diametrically opposed to said V-shaped extensions to enter the comating notches in the clampv member to prevent rotation of said clamp member and simultaneously cause said extensions to be forced inwardly of the notches in the clamp member to Widen the split and cause said clamp member to forcefully engage the support end portion and base to render said support immovable.

11. A device of the character described comprising a pair of longitudinal guide members disposed in laterally spaced relation, sighting means adjacent one end of said guide members, a support slidable longitudinally of said guide members, a pair of target holders each adapted to carry a target, said target holders being mounted on the support for movement toward and away from each other, a follower carried by each of said target holders and mounted with a respective guide member for longitudinal movement therealong, and adjustment means for altering the extent of separation between the opposed ends of said guide member With respect to the corresponding ends of the other guide member, whereby the angular relation of and the spacing between said corresponding ends of the guide members may be adjusted to desired relations to control the paths of movement of the targets in operation of the device.

ACHARLES A. ELLIS. HENRY B. COLE.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,895,746 Bates Jan. 31, 1933 2,091,173 Wottring Aug. 24, 1937 2,362,857 Renshaw Nov. 14, 1944 2,414,649 Kelly Jan. 2l, 1947 2,422,384 Alexander June 1'7I 1947 2,473,651 Katz June 21, 1949 

